Simply set the screens to show the field to the relevant groups (Administration -> Screens). For example if you'd like all to see the value but only managers to edit / create it then set the "view" screen to show the field to the "Eveyone" group and the edit / create screens to show it to only the Managers group.

Hello!

I followed your instructions and created the differing screen permissions and applied them to the ticket type in question;

However the problem persists, as users can just edit the value in-line.

Removing the custom field from 'in-line' doesn't help as the field is still shown in the 'Additional Information' panel, where it can anyway be edited in-line regardless of rights.

Did I miss something in my configuration perhaps?

Cheers, -Marc